The unicellular group, dinoflagellates, can be found in fresh water, preying upon other protozoa.
Dinoflagellates contain eyespots and two flagella enabling them to find and move towards prey. Every day they undergo mitosis and in some cases this forms ‘red tides’.
State which functions of life have been described in this passage on dinoflagellates.
Whilst examining the Amoeba, the student also measured the length of the organelles present, including the nucleus. The length of the nucleus on the microscope image was 28 000 µm.
If the student was examining the nucleus using the same magnification as part (a), in millimetres (mm), calculate the actual size of the nucleus.
The freshwater habitats of Amoeba proteus may contain organisms that have more complex structures eg. freshwater snails. The snails have primitive gills enabling them to breathe under water and mucus-producing glands that allow them to hibernate when the water freezes.
Independently these structures have different properties but when combined they provide the snails with survival properties in the aquatic environment.
State the type of property that multicellular organisms, like the freshwater snail, have.
